Process and apparatus for locally annealing metal plates



Febu 20g 1923. 1,446,354.

R. s. SMITH ET AL.

-PROCESS AND APPARATUS FOR LOCALLY ANNEALING METAL PLATES.

FILED OCT=22.1920.

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or border of the metal embraced within the Patented Feb. 20, i123@ didi,

REUBEN STANLEY SMITH, OF. MILWAUKEE, AND RICHARD STRESAU, OF WAWAU- TDSA, WISCONSIN, ASSIGNORS TO A. '0. SMITH CORPORATION, OF MILWAUKEE,

WISCONSIN, CORPORATION OF NEW YORK.

PROCESS IEIND .APPARATUS FOR IJOCALLY AITNEALING- METAL PLATES.

l Application led October 22, 1,9120. Serial No. 418,709.

Toall whom t may cow/cem.'

Be it known that we,.R-EUBEN STANLEY SMITH and RioHARD S'rnnsAU, citizens of the' United States, and residing-, respectively, in the cities ot' Milwaukee and Wauwautosa, county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Processes and Apparatus for Locall Annealing Metal Plates (Case #168) and we do declare the following to be a clear, exact, and .complete description thereof, such as will enable others skilled in the ait to which the invention pertains to make and use the same, reference being had to the accompanying drawing as showing one form of apparatus in which the invention has been embodied and by means of which the process may be reduced to practice.

Our invention relates to a process and apparatus for annealing metal plates, and,

without limiting the uses of the invention,l

we may state that itis particularly designed for annealing the concave marginal portions ot' ,the sheet metal blanks used in constructing the curved side bars and cross bars of an automobile frame.

The present invention relates to an improvement in the process of local annealing disclosed in application Serial #381,87 6, filed May 17, y1920, by R. Stanley Smith, one ot' the parties hereto, and Thorvald Hansen.

ln the manufacture of automobile frames,

the side bars and cross bars which are per-y manently united to constitute the structural unit of the `frame, are formed from sheet metal blanks, which are punched from metal strips or plates, and 4which have their side marginal portions turned so as to stand normal to the, plane of the body of the blank, and thus form a reinforced flanged channel bar. rllhe engineering construction of many automobiles necessitates the use of curved side bars and cross bars in the frame unit, and serious mechanical difficulties have been encountered in producing such curved side and cross bars, in the particular forms prescribed by the designers of the automobile.`

These diiiiculties arise from the `fact that in the drawing opera-tion, by which the side margins of the .blank are turned so as to constitute the upstanding flanges, the edge area of theconcave flanged portion of the bar is required to be materially stretched or elongated, to accommodate it to the lengthcned lines of the up'turned flange at such later time, when a load is placed uponthc structure.

We have discovered that the dies of .the blanking press, in cutting through the metal of the strip orplate, produce a crystallization of the metal along the line of the action ot the dies. The presence of such crystallization at the edges of the blank, creates a weakened condition, so that the `metal at the 'edge of the blank in `the concave portion yields quite readily under the strain imposed upon it in the dra-wing operation, in consequence of which the metal is sometimes torn, and if not torn, is so weakcned as to be subject to the breakage adverted to.

For the purpose of overcoming the objection incident to the older practice of turning the concave margins of the blank,l ithas beenthe custom to subject the entire blank to an application of heat, whereby the crystalline structure is removed from the blank adjacent the cut edges, and the dies of the drawing press may turn thelconcave marginal portions of the blank Without the adverse conditions usually resiiltin from the drawing operation. But the su jection of Athe whole of the blank to heat treatment -s disadvantageous, inasmuch as the blank iS thus softened in areas in which it is desirable that theoriginal, rigid state of the metal, remain undisturbed.

`We have found by extensive experiment and use t-hatpit is not necessary to anneal the whole of the blank, but that we may attain the results desired by merely locally annealing the blank in the 'area of the curved strainsiincident to the practice of the older "apparatus referred to is equipped with process. This local annealing lwe achieve with a very great economy in the use of the heat employed for that purpose, as'compared with the more recent process of annealing the whole of the blank, and at the same time, the initial rigid qualities of the major of the blanks are preserved.

Our invention resides in an apparatus which. has been so constructed that the blanks 'are fed into the field of the heating elements, and permitted to remain within suchfield for a length of time sufficient to brin about the proper annealing of the blan s in the concave edges thereof. The

means which convey the blanks in a stepby-step movement, so that each blank is permitted to remain within the range of the heat for a length of time which is approximatelyequal to that required to irnpart the step-by-step feeding movement ,to

the series-of blanks. The particular apparatus illustrated and hereinafter described constitutes merely onev form of device whereby our improved process of feeding the blanks in timed relation tothe action of the heating elements may be carried out.

The novel features of our invention will be recited in the claims appended to-this specification.

ln the.drawings which accompany and form part of this application, f

Figure 1 is a plan view yshowing our newly devised apparatus for presenting the blanks in a position for the local annealing hereinbefore referred to, and showing also thearrangement of the device by means of which the heat treatment is applied to the concave marginal portions of the blank.

Fig. 2 is a View in side elevation of' the u apparatus shown in Fig. V1, looking toward the latter figure.

F ig. 3 is an enlarged sectional view show.- ing a portion of the metal blank and illustrating the manner in which the heat is aplie p In the drawings, the numeral 10 designates a pair of rails which may be' supported by any suitable means, preferably in a horizontal position. .The sheet metal blanks A, which are to be subjected to heat treatment. are designed to be moved along the `upper surfaces of the rails 10, and to be supported by the said rails in such movement. l

A longitudinally reciprocating lframe 11, located conveniently beneath the supporting rails 10, may be moved within a limited traverse by any suitable mechanism. In the field, and adjacent one extreme of the reciprocating movement of the frame 11, a series of gas burners 12 isarranged.. These gas burnersr12 are connected with and suparea lported by a supply pipe 13. The'number and location of theA gas burners l2, will be forward position under one reciprocation of the slide 11.

The slide 11 is provided with a series of pairs of uniformly spaced upstanding arms 14C, upon the'upper end ofeach of which a finger 15 is pivoted, as at 16. The number of pairs of arms 14, with complemrntal fingers 15, will be such as constitute a conveyor sufficient in length to carry the blanks in step-by-step movements through the apparatus. Each of the ypivoted fingers 15 is provided with a counter-balance 17, which serves to maintain the finger 15 in an' approximately vertical position, with the upper end of such-fingers inengagement with a stop 18, formed at the upper end of the arm 14, and extending across .and at one rear edge of thelblank, such notch lying normally in the plane of the upper surface of the rails l0, above which the tips of the fingers 15 project slightly.y But the notches `19 in the tips of the fingers 15, are not essential vto the successful operation of the apparatus, and may be omitted as a structural feature, if desired.

In the operation ofour improved appa-` y ratus, the blanks A, placed upon the slide 11, are 4fed in spaced relation by a step-bystep movement in the reciprocations of the said slide. ment of the blanks is due to the engagement of the projecting tips -of the fingers 15, with the rear edge of the blank A, and the re- `ciprocations of the slide 11 will carry the said blanks successively into'a'position of rest, adjacent the gas burnersl 12. With the retirement of one set of 'fingers 15, after thus positioning one of the blanks A, the reciprocation of the slide 11 will bring the next leading or forward set of fingers 15 at the rear of the gas burners and position This forward feeding move-` them behind the blank A, which had been Y previously placed within the field of action of the said gas burners. The pivotal arrangement of the fingers 15. upon theposts 14, will permit the said' fingers to turn upon their pivots and pass under the blank A, previously positioned for heat treatment. The counter-Weights 17 automatically cause the tips of the fingers 15 to. rise above'the rails 10, and engage the rear edge of the a manner which will be understood from whathas been stated in the foregoing.

In the intervals of the step-by-step movement of the blanks A, into and out of posi- -tion for the application of the heat by means of the gas burners 12, it is desirable, for reasons of economy, that the ed'ective iiame of the gas burners be reduced. rllhis result we achieve by providing automatic devices for `controlling theiiow of gas, and reducing the pressure of the latter during the inter-s vals of the movement of the blanksA .over

- they rails 10. The said devices are constituted of a plate 20, which lis attached to the-slide 11. The said plate 20 istpro'vided with a slot 21, in which travels a pin 22,

lprojecting from an arm 23, wh'ch latter has a. loose connection, formed as a slot 24, embracing the Jllattened sides of the stem 25, of a valve or cut-ofi' 26, coupled into the assu l ie13. g ln tibi 5inliniiu'nent of the slide 11 to the right, as indicated by the full-line arrow in Fig. 2, the pin 22 on the arm 23 will reach the end of the slot 21, which movement of the parts will rotate the stem of the valve, to open the latter and permit the gas flame to play upon the concave marginal portions of the blank A, at the moment that the latter has been moved into its effective position. Thegas will continue to How during the reverse movement of the slide' 11 'to the left as' indicated by the dotted arrow'in` `ment the blank A which has been heat treated will be removed from its position in proximity to the gas burners, and a fresh blank will be positioned. -At this moment,

the gas will again be turned on, and the newly positioned blank A be subjected to treatment, as before. I

Fig?, illustrates somewhat more clearly the manner of the application of the heat to the concave portions of the edge 'of the blank. The eiect of v the application of heat to such concave portions, is to destroy the crystalline formation in the edge of the blank, and. thus counteract the liability of rlhis forward movement of the slide the concave marginal portions of the blank to tear when subjected to`the drawingv operation, by reason. of the weakness of the metal due to the presence of crystallization created in the blanking operation.

The actuating vmeans for reciprocating the slide 11, will be so timed in its operation that the blanks which are to be heat treated will be intermittingly advanced in a regular spaced procession to position with each blank in succession in the field of the gas burners, and be allowed to remain at rest in such position for the action of thei'lame thereon for a given length of time, which vwill be predetermined as suiiicient to enable the proper heating of the blank to be edected. The time allotted for the heating ofthe metall blanks will be approximately onehalf of the cycle of operation of the apparatus,'the other half of the said 'cycle being consumed in the step-by-step feeding movement of the succession of blanks.`

While we have disclosed an apparatus in whlch the heaters occupy a relatively fixed position, and the blanks to be treated are passed with an intermitting movement through the heating iield,.it will be within the scope of. our invention to construct the annealing apparatus so that themetal plates or blanks will be fed in a continuous procession, and to arrange the heaters so as to move with the blanks for a distance` sufficient to permit a properamount of heat to be applied to the blanks while in transit. lin

other Words, the heatersmayv be caused to reciprocate along the path of movement of the blanks, and while traveling therewith for a time, participate in such movement,

for the attainmentl ofl the purposes of our n invention. f Y

rilhe character of the gas used, its pressure, and the extent of time during which the tlame will be maintained,are factors'to be v determined by the structure of the particular blanks which it is desired to treat. Such adjustments as are necessary to secure elicient results may be made readily by any person skilled in the art to which the present invention. appertains.

Having thus described our invention, what we claim and desire to secure by Letters Patent off the United States, is:

i. The method of locally annealing which 'consists in the arrangement of heatejisin a field, intermittingly feeding a succession of metal plates in 'spaced 'procession into the heating field, wherein each plate is subjected to action by the heat in the areas to be annealed, during the intervals of the intermitting feeding movements.

`2. rllhe method of locally annealing metal plates, `which consists in inter'mittingly feeding .a succession .of metal plates in spaced procession through a heating iieid, and

step-by-step movements into the heating field, subjecting the plates in succession to action by the heat in the areas to 'be annealed while in such field in the intervals of the feeding movements of the plates, and reducing the volume of heat during such movements.

t. rlhe method of loc-ally annealing, which consists in supporting a plurality of spaced and aligned heaters, intermittingly feeding a succession of Lmetal plates for action thereon by the heaters to anneal the said plates in areas contiguous to the heaters in the intervals of the feeding movements of the plates, and controlling the volume of heat in the movement of the plates.

5. Apparatus for annealing loca-l areas in metal plates, comprising a ser-ies of heaters and means for intermittingly feedingmetal plates in spaced succession into the field of the heaters for action thereon in the inter vals of the feeding movements.

6. Apparatus for annealing local areas in metal plates, said appara-tus comprising means adapted to maintain a heating field in' which the metal plates are successively positioned for action by said heating means, and intermittingly operating means for moving the plates into and out of position in the heating fieldi 7. ln an apparatus for annealing local areas in metal plates, a series of gas burners, means for intermittingly moving 'a succession of plates into the field of the said burners, and means operativein the movement of the plates to control the flow of gas to the burners. 4

SQIn an apparatus for annealing local areas in` metal plates, the combination of a gas burner` with means for feeding a met-al plate into the field of the burner, and connections from said feeding means operative to control the fiow of gas to the said burner. 9. In an apparatus .for annealing local areas in metal plates, the combination of a stationary gas burner, with automatic-intermittingly operating means for positioning a metal plate in the field of the burner and for removing the said plate from such field after treatment.

.10. In anv apparatus for annealing local areas in metal plates, the combination of a gas burner, with a reciprocating slide adapted to feed a metal plate into and outof the field of action of the said burner, and connections whereby the said 'slide at the conclusion of its plate feeding movement -acts to turn on the supply of gas and at the conclu- @44eme sion of its reverse movement to reduce the flow of the gas.

11. vIn an apparatus forannealing local areas in metal plates, `a support for the metal plates to be heat treated,- a gas burner arranged in the path of movement of the plates over their support, and means for intermittinglymoving the plates in spaced succession into and out of the heating field. 12. ln an apparatus for annealing local areas in metal plates, a 'sup-port over which the path. of the forward movement of the plates to be heat treated, feeding means to position the plates in succession in the heating field, and connections from said feeding means operative to maintain the gas flame while the said plates are positioned as aforesaid, and to reduce the flame when the plates are removed from the said field.

14E. 'ln an apparatus for annealing local areas in metal plates, a gas supply comprismg stationary burners, affixed support over which the metal plates to be; heat treated may be moved, and means for moving the plates over the support in spaced succession and positioning them in the field of action of the burners.

15. ln an apparatus for annealing local areas in metal plates, a gas supply comiprising stationary burners, a support over which the metal plates to be heat treated may be moved, means for moving 'the plates, and connections from the said means adapted to control the flow of gas to the burners.

16. In an apparatus for annealing local areas in meta-l plates, a support for the lates to be heat treated, a gas heater in )red conjunction with the said sup-port', a

yvalve controlling the ,flow of gas to the heater, (means for moving the plates on the.

support and positioning them in the field of action of the gas burner, and connections between the said means and the valve, whereby the flow of gas is caused to rise when the plates are moved intoefl'ective re- A lation tothe heater. v

ln testimony whereof, we have signed our names at Milwaukee, this 7th day of October, 1920. R. STANLEY SMITH'. R. STRESAU. Witnesses:

W. F. WooLARD, ELIZABETH MURRAY.' 

